Keycloak-services: keycloak-services: stateless token preferred_username fallback enables identity rebinding

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-96447
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-06 06:16:44 UTC
Updated2026-11-06 18:18:27 UTC
DescriptionA flaw was found in the TokenManager component of Keycloak, an open-source identity and access management solution. The issue occurs during the validation of stateless access tokens when the original user ID no longer exists. Keycloak incorrectly falls back to using the username to identify the user without verifying if the identity matches the original token subject. This could allow an attacker with an old token to gain access to a newly created service account if it shares the same client ID as a previously deleted one.

Risk And Classification

Primary CVSS: v3.1 4.2 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

Problem Types: CWE-287 | CWE-287 Improper Authentication

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.2MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
3.1CNACVSS4.2MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat Build Of Keycloak 26.6 unaffected 26.6.8-2 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.6 unaffected 26.6-24 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.6 unaffected 26.6-24 * rpm Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.6.8 Not specified Not specified
CNA Red Hat Red Hat Build Of Keycloak 26.6.8 Not specified Not specified
CNA Red Hat Red Hat Single Sign-On 7 Not specified Not specified

References

ReferenceSourceLinkTags
access.redhat.com/security/cve/CVE-2026-96447 [email protected] access.redhat.com
access.redhat.com/errata/RHSA-2026:95761 [email protected] access.redhat.com
access.redhat.com/errata/RHSA-2026:95762 [email protected] access.redhat.com
bugzilla.redhat.com/show_bug.cgi [email protected] bugzilla.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank Bruno Oliveira of IBM in collaboration with OpenAI for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-09-22T12:56:03.000ZReported to Red Hat.
CNA2026-11-05T00:00:00.000ZMade public.

Workarounds

CNA: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

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